fs/ufs/namei.c

   1 /*
   2  * linux/fs/ufs/namei.c
   3  *
   4  * Migration to usage of "page cache" on May 2006 by
   5  * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
   6  *
   7  * Copyright (C) 1998
   8  * Daniel Pirkl <daniel.pirkl@email.cz>
   9  * Charles University, Faculty of Mathematics and Physics
  10  *
  11  *  from
  12  *
  13  *  linux/fs/ext2/namei.c
  14  *
  15  * Copyright (C) 1992, 1993, 1994, 1995
  16  * Remy Card (card@masi.ibp.fr)
  17  * Laboratoire MASI - Institut Blaise Pascal
  18  * Universite Pierre et Marie Curie (Paris VI)
  19  *
  20  *  from
  21  *
  22  *  linux/fs/minix/namei.c
  23  *
  24  *  Copyright (C) 1991, 1992  Linus Torvalds
  25  *
  26  *  Big-endian to little-endian byte-swapping/bitmaps by
  27  *        David S. Miller (davem@caip.rutgers.edu), 1995
  28  */
  29
  30 #include <linux/time.h>
  31 #include <linux/fs.h>
  32
  33 #include "ufs_fs.h"
  34 #include "ufs.h"
  35 #include "util.h"
  36
  37 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
  38 {
  39         int err = ufs_add_link(dentry, inode);
  40         if (!err) {
  41                 unlock_new_inode(inode);
  42                 d_instantiate(dentry, inode);
  43                 return 0;
  44         }
  45         inode_dec_link_count(inode);
  46         unlock_new_inode(inode);
  47         iput(inode);
  48         return err;
  49 }
  50
  51 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
  52 {
  53         struct inode * inode = NULL;
  54         ino_t ino;
  55
  56         if (dentry->d_name.len > UFS_MAXNAMLEN)
  57                 return ERR_PTR(-ENAMETOOLONG);
  58
  59         lock_ufs(dir->i_sb);
  60         ino = ufs_inode_by_name(dir, &dentry->d_name);
  61         if (ino)
  62                 inode = ufs_iget(dir->i_sb, ino);
  63         unlock_ufs(dir->i_sb);
  64         return d_splice_alias(inode, dentry);
  65 }
  66
  67 /*
  68  * By the time this is called, we already have created
  69  * the directory cache entry for the new file, but it
  70  * is so far negative - it has no inode.
  71  *
  72  * If the create succeeds, we fill in the inode information
  73  * with d_instantiate().
  74  */
  75 static int ufs_create (struct inode * dir, struct dentry * dentry, umode_t mode,
  76                 bool excl)
  77 {
  78         struct inode *inode;
  79         int err;
  80
  81         UFSD("BEGIN\n");
  82
  83         inode = ufs_new_inode(dir, mode);
  84         err = PTR_ERR(inode);
  85
  86         if (!IS_ERR(inode)) {
  87                 inode->i_op = &ufs_file_inode_operations;
  88                 inode->i_fop = &ufs_file_operations;
  89                 inode->i_mapping->a_ops = &ufs_aops;
  90                 mark_inode_dirty(inode);
  91                 lock_ufs(dir->i_sb);
  92                 err = ufs_add_nondir(dentry, inode);
  93                 unlock_ufs(dir->i_sb);
  94         }
  95         UFSD("END: err=%d\n", err);
  96         return err;
  97 }
  98
  99 static int ufs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
 100 {
 101         struct inode *inode;
 102         int err;
 103
 104         if (!old_valid_dev(rdev))
 105                 return -EINVAL;
 106
 107         inode = ufs_new_inode(dir, mode);
 108         err = PTR_ERR(inode);
 109         if (!IS_ERR(inode)) {
 110                 init_special_inode(inode, mode, rdev);
 111                 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
 112                 mark_inode_dirty(inode);
 113                 lock_ufs(dir->i_sb);
 114                 err = ufs_add_nondir(dentry, inode);
 115                 unlock_ufs(dir->i_sb);
 116         }
 117         return err;
 118 }
 119
 120 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
 121         const char * symname)
 122 {
 123         struct super_block * sb = dir->i_sb;
 124         int err = -ENAMETOOLONG;
 125         unsigned l = strlen(symname)+1;
 126         struct inode * inode;
 127
 128         if (l > sb->s_blocksize)
 129                 goto out_notlocked;
 130
 131         inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
 132         err = PTR_ERR(inode);
 133         if (IS_ERR(inode))
 134                 goto out_notlocked;
 135
 136         lock_ufs(dir->i_sb);
 137         if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
 138                 /* slow symlink */
 139                 inode->i_op = &ufs_symlink_inode_operations;
 140                 inode->i_mapping->a_ops = &ufs_aops;
 141                 err = page_symlink(inode, symname, l);
 142                 if (err)
 143                         goto out_fail;
 144         } else {
 145                 /* fast symlink */
 146                 inode->i_op = &ufs_fast_symlink_inode_operations;
 147                 memcpy(UFS_I(inode)->i_u1.i_symlink, symname, l);
 148                 inode->i_size = l-1;
 149         }
 150         mark_inode_dirty(inode);
 151
 152         err = ufs_add_nondir(dentry, inode);
 153 out:
 154         unlock_ufs(dir->i_sb);
 155 out_notlocked:
 156         return err;
 157
 158 out_fail:
 159         inode_dec_link_count(inode);
 160         unlock_new_inode(inode);
 161         iput(inode);
 162         goto out;
 163 }
 164
 165 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
 166         struct dentry *dentry)
 167 {
 168         struct inode *inode = old_dentry->d_inode;
 169         int error;
 170
 171         lock_ufs(dir->i_sb);
 172
 173         inode->i_ctime = CURRENT_TIME_SEC;
 174         inode_inc_link_count(inode);
 175         ihold(inode);
 176
 177         error = ufs_add_nondir(dentry, inode);
 178         unlock_ufs(dir->i_sb);
 179         return error;
 180 }
 181
 182 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
 183 {
 184         struct inode * inode;
 185         int err;
 186
 187         inode = ufs_new_inode(dir, S_IFDIR|mode);
 188         if (IS_ERR(inode))
 189                 return PTR_ERR(inode);
 190
 191         inode->i_op = &ufs_dir_inode_operations;
 192         inode->i_fop = &ufs_dir_operations;
 193         inode->i_mapping->a_ops = &ufs_aops;
 194
 195         inode_inc_link_count(inode);
 196
 197         lock_ufs(dir->i_sb);
 198         inode_inc_link_count(dir);
 199
 200         err = ufs_make_empty(inode, dir);
 201         if (err)
 202                 goto out_fail;
 203
 204         err = ufs_add_link(dentry, inode);
 205         if (err)
 206                 goto out_fail;
 207         unlock_ufs(dir->i_sb);
 208
 209         d_instantiate(dentry, inode);
 210 out:
 211         return err;
 212
 213 out_fail:
 214         inode_dec_link_count(inode);
 215         inode_dec_link_count(inode);
 216         unlock_new_inode(inode);
 217         iput (inode);
 218         inode_dec_link_count(dir);
 219         unlock_ufs(dir->i_sb);
 220         goto out;
 221 }
 222
 223 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
 224 {
 225         struct inode * inode = dentry->d_inode;
 226         struct ufs_dir_entry *de;
 227         struct page *page;
 228         int err = -ENOENT;
 229
 230         de = ufs_find_entry(dir, &dentry->d_name, &page);
 231         if (!de)
 232                 goto out;
 233
 234         err = ufs_delete_entry(dir, de, page);
 235         if (err)
 236                 goto out;
 237
 238         inode->i_ctime = dir->i_ctime;
 239         inode_dec_link_count(inode);
 240         err = 0;
 241 out:
 242         return err;
 243 }
 244
 245 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 246 {
 247         struct inode * inode = dentry->d_inode;
 248         int err= -ENOTEMPTY;
 249
 250         lock_ufs(dir->i_sb);
 251         if (ufs_empty_dir (inode)) {
 252                 err = ufs_unlink(dir, dentry);
 253                 if (!err) {
 254                         inode->i_size = 0;
 255                         inode_dec_link_count(inode);
 256                         inode_dec_link_count(dir);
 257                 }
 258         }
 259         unlock_ufs(dir->i_sb);
 260         return err;
 261 }
 262
 263 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 264                       struct inode *new_dir, struct dentry *new_dentry)
 265 {
 266         struct inode *old_inode = old_dentry->d_inode;
 267         struct inode *new_inode = new_dentry->d_inode;
 268         struct page *dir_page = NULL;
 269         struct ufs_dir_entry * dir_de = NULL;
 270         struct page *old_page;
 271         struct ufs_dir_entry *old_de;
 272         int err = -ENOENT;
 273
 274         old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
 275         if (!old_de)
 276                 goto out;
 277
 278         if (S_ISDIR(old_inode->i_mode)) {
 279                 err = -EIO;
 280                 dir_de = ufs_dotdot(old_inode, &dir_page);
 281                 if (!dir_de)
 282                         goto out_old;
 283         }
 284
 285         if (new_inode) {
 286                 struct page *new_page;
 287                 struct ufs_dir_entry *new_de;
 288
 289                 err = -ENOTEMPTY;
 290                 if (dir_de && !ufs_empty_dir(new_inode))
 291                         goto out_dir;
 292
 293                 err = -ENOENT;
 294                 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 295                 if (!new_de)
 296                         goto out_dir;
 297                 ufs_set_link(new_dir, new_de, new_page, old_inode);
 298                 new_inode->i_ctime = CURRENT_TIME_SEC;
 299                 if (dir_de)
 300                         drop_nlink(new_inode);
 301                 inode_dec_link_count(new_inode);
 302         } else {
 303                 err = ufs_add_link(new_dentry, old_inode);
 304                 if (err)
 305                         goto out_dir;
 306                 if (dir_de)
 307                         inode_inc_link_count(new_dir);
 308         }
 309
 310         /*
 311          * Like most other Unix systems, set the ctime for inodes on a
 312          * rename.
 313          */
 314         old_inode->i_ctime = CURRENT_TIME_SEC;
 315
 316         ufs_delete_entry(old_dir, old_de, old_page);
 317         mark_inode_dirty(old_inode);
 318
 319         if (dir_de) {
 320                 ufs_set_link(old_inode, dir_de, dir_page, new_dir);
 321                 inode_dec_link_count(old_dir);
 322         }
 323         return 0;
 324
 325
 326 out_dir:
 327         if (dir_de) {
 328                 kunmap(dir_page);
 329                 page_cache_release(dir_page);
 330         }
 331 out_old:
 332         kunmap(old_page);
 333         page_cache_release(old_page);
 334 out:
 335         return err;
 336 }
 337
 338 const struct inode_operations ufs_dir_inode_operations = {
 339         .create         = ufs_create,
 340         .lookup         = ufs_lookup,
 341         .link           = ufs_link,
 342         .unlink         = ufs_unlink,
 343         .symlink        = ufs_symlink,
 344         .mkdir          = ufs_mkdir,
 345         .rmdir          = ufs_rmdir,
 346         .mknod          = ufs_mknod,
 347         .rename         = ufs_rename,
 348 };